The issue with keys is the fact that they can be found during the trial. There's no way to play around that because it's pure RNG. It also wouldn't hurt if they were made more visible in the lobby. I sometimes find a broken key and still have it equipped the next trial because I literally don't notice it and forget it's even there.
Moris are fine, though. They have awesome animations and are one of the few things that actually make survivors scared of the killer - they put the "horror" back in this horror game.

I think he can be annoying to play against, but that's about it. The only thing that could be considered OP about him is the fact that he can guard a 3-gen basically forever, but that's easy enough to avoid if you have any map awareness.